A short-range magnetic field system is associated with short-range wireless contact standards including Erma 340 and ISO/IEC 18092 that use magnetic induction between neighboring devices to establish communication in all directions.
For example, the short-range magnetic field system may transmit data at a data rate up to 424 kilobits per second (Kbps) within a range of 20 centimeters (cm) using a frequency of 13.56 megahertz (MHz), and may be used to make a payment and to download content to a mobile device such as a cellular phone and through a wireless broadband internet (WiBro).
Magnetic field communication technology is a wireless communication system technology using magnetic induction that enables wireless communication even in extreme environments, for example, in an environment in which metals are used, an underwater environment, an underground environment, and a collapsed or destroyed building.
Because the magnetic field communication technology uses a low frequency unlike recent high frequency communication technology, a degree of penetration may be relatively high. Thus, the magnetic field communication technology uses a principle that a frequency loss may be less even when a frequency passes through different mediums such as soil, water, and concrete.
Similarly, the magnetic field communication technology may have a communication range wider than that of near field communication (NFC) technology and radio frequency identification (RFID) technology and consume a small amount of power. Thus, the magnetic field communication technology is suitable for establishing a sensor network for monitoring management of the underground environment, the underwater environment, and a harmful environment.
For example, when an underground facility is managed using magnetic communication, an amount of damage caused by a leakage from water mains may be reduced by more than 20%.
In addition, the short-range magnetic field system may be applied to a wireless power transfer (WPT) method, also referred to as a wireless energy transfer method or a wireless charge method, in an electronic device, and the WPT method may have a great number of advantages.
Firstly, in terms of convenience, a user may not need to unnecessarily carry a plurality of cable chargers in order to charge batteries of devices such as mobile phones, tablet computers, and notebook computers. Instead, the user may dispose a single wireless charger in an area such as a conference room, a coffee shop, a waiting area at an airport, and a house. The user may charge electronic devices by simply disposing the wireless charger close to the electronic devices without using a wired connection. A WPT system may be standardized such that a plurality of devices of which models and producers are different are charged by a single wireless charger. Thus, a universal charging standard may be possible.
Secondly, in terms of practicality, as number of physical electrical outlets to be used in the area such as the conference room the coffee shop, and the waiting area at the airport may be limited. Thus, a number of users who are able to use the electrical outlets may be also limited. However, the WPT system ma solve such problems and enable the users to charge the devices in a faster and easier manner.
Thirdly, in terms of penetrability, a wireless power may penetrate through various objects such as a tree, plastic, paper, and fabric. Thus, a power may be transferrable even in places where a physical wired connection is unadvisable or impossible, for example, where an implant apparatus is used, in the underwater environment, or where a charging is performed while moving.
Fourthly, in terms of greening, the WPT system follows a universal charging solution (UCS) suggested by all international telecommunication union (ITU) which is a specialized agency of the United Nations. Essentially the UCS may allow all handsets to be charged with a same wireless charger such that an amount of standby energy consumption will be reduced 50 percent, 51,000 tons of surplus chargers will be removed, and 13.6 million tons of greenhouse gas emissions will be reduced every year.
Accordingly, a variety of research is being done on the short-range magnetic field system and the WPT method.
For example, Korean Patent Laid-Open Publication No. 2012-0019195 published on Feb. 24, 2012 discloses an apparatus for transmitting magnetic resonance power.